1. Field of the Invention
The present invention relates to a process for producing a 2-hydrocarbyl-2-adamantyl acrylate compound which gains industrial attention as a material for ArF excimer laser resists and high performance polymers.
2. Description of the Prior Art
In the known production of a 2-alkyl-2-adamantyl (meth)acrylate compound from a 2-adamantanone compound corresponding to its ester moiety, the 2-adamantanone compound is converted into a corresponding 2-alkyl-2-adamantanol compound, and then the 2-alkyl-2-adamantanol compound is reacted with (meth)acrylic acid or a (meth)acryloyl halide.
K. Nozaki et al., Jpn. J. Appl. Phys., 35,528(1996) report to synthesize 2-methyl-2-adamantyl methacrylate by the esterification reaction between 2-methyl-2-adamantanol and methacryloyl chloride. Japanese Patent Application Laid-Open No. 2000-229911 propose to synthesize a 2-alkyl-2-adamantyl (meth)acrylate by the reaction of a corresponding 2-alkyl-2-adamantanol compound with (meth)acryloyl chloride. Japanese Patent Application Laid-Open No. 2000-309558 discloses a reaction of a corresponding 2-alkyl-2-adamantanol compound or its metal salt with a (meth)acryloyl halide.
Japanese Patent Application Laid-Open No. 10-182552 discloses a process for producing an ester of tertiary alcohol without separating and purifying a tertiary alcohol, in which a starting ketone compound is reacted with a carboxylic acid halide in the presence of an organometallic compound to directly obtain the ester of tertiary alcohol. However, a (meth)acryloyl halide used as the esterification reagent is expensive and intractable, and contains various by-products which are difficult to remove. In addition, the (meth)acryloyl halide by-produces an alkyladamantyl halide which generates acid during distillation to decompose the target 2-alkyl-2-adamantyl (meth)acrylate compound, thereby significantly reducing the yield.
Japanese Patent Application Laid-Open No. 2000-97924 proposes to convert the alkyladamantyl halide to a compound which does not generate acid during distillation by contacting a 2-alkyl-2-adamantyl (meth)acrylate compound containing the alkyladamantyl halide with an alkali compound, thereby preventing the yield from being lowered. Japanese Patent Application Laid-Open No. 2000-229911 proposes a method for producing the 2-alkyl-2-adamantyl (meth)acrylate compound in high yields by using an acid halide prepared by reacting (meth)acrylic acid with benzoyl chloride or phosphorus trichloride.
However, since a production method using an acid halide should be carried out in a specific manner, it has been demanded to develop a production method which is easily operated in industrial scale and produces a 2-hydrocarbyl-2-adamantyl acrylate compound with high yields without using acid halide.
An object of the present invention is to provide a process for producing a 2-hydrocarbyl-2-adamantyl acrylate compound easily and stably with high yields from a 2-adamantanone compound without using a (meth)acryloyl halide.
As a result of extensive study in view of attaining the above object, the inventors have found that the 2-hydrocarbyl-2-adamantyl acrylate compound is efficiently produced from a 2-adamantanone compound by using a (meth)acrylic ester and/or an acrylic anhydride compound in place of the (meth)acryloyl halide. On the basis of this finding, the present invention has been accomplished.
Thus, the present invention provides a process for producing a 2-hydrocarbyl-2-adamantyl acrylate compound represented by the following
Formula 6: 
wherein R1 is a hydrocarbyl group, R2 is a hydrogen atom or an alkyl group, and Y is a hydrogen atom, an alkyl group, a hydroxyl group, or a halogen atom, and n is an integer of 1 to 14;
the process comprising a step of reacting a 2-adamantanone compound represented by the following Formula 1: 
wherein Y and n are the same as defined above;
with at least one organometallic compound and at least one acrylic compound, the organometallic compound being represented by the following Formula 2 or 3:
R1MgXxe2x80x83xe2x80x83(2)
R1Lixe2x80x83xe2x80x83(3)
wherein R1 is the same as defined above, and X is a halogen atom;
and the acrylic compound being represented by the following Formula 4 or 5: 
wherein R2 is the same as defined above, and R3 is an alkyl group.
The 2-adamantanone compound (2-adamantanone and its derivatives) used as a starting material is represented by the following Formula 1: 
In Formula 1, Y is a hydrogen atom, an alkyl group, a hydroxyl group, or a halogen atom. The alkyl group is preferably a C1-C10 alkyl such as methyl group, ethyl group, isopropyl group and amyl group. Examples of halogen atom is chlorine atom, bromine atom and iodine atom. The suffix xe2x80x9cnxe2x80x9d is an integer of 1 to 14, preferably 1 to 4. If n is 2 or more, two or more Y substituents may be the same as or different from each other. Particularly preferred 2-adamantanone compound is 2-adamantanone.
In the process of the present invention, a Grignard reagent represented by Formula 2 and/or an organolithium compound represented by Formula 3 is used as the organometallic compound.
R1MgXxe2x80x83xe2x80x83(2)
R1Lixe2x80x83xe2x80x83(3)
In Formulas 2 and 3, R1 is a hydrocarbyl group, preferably an aliphatic, alicyclic or aromatic hydrocarbyl group having 1 to 10 carbon atoms, more preferably methyl group, ethyl group, propyl group, butyl group or phenyl group. X is a halogen such as chlorine, bromine and iodine. Specific Grignard reagent may be CH3MgBr, C2H5MgBr, or C4H9MgBr, and a specific organolithium compound may be CH3Li, C2H5Li or C4H9Li.
The Grignard reagent and the organolithium compound is added to the reaction system in the form of solution. As the solvent, usable are ether compounds such as tetrahydrofuran and diethyl ether; hydrocarbon compounds such as hexane, heptane and cyclohexane; and halogen compounds such as carbon tetrachloride and dichloromethane, although not limited thereto and another solvent is usable as far as inert to the reaction.
The Grignard reagent or the organolithium compound is used in an amount of 1 to 10 equivalents, preferably 1 to 2 equivalents based on the starting 2-adamantanone compound. Although the Grignard reagent or the organolithium compound may be added to the reaction system in any manner and at any addition speed, but preferably added at a speed so as to avoid the abnormal rise of the reaction temperature.
In the process of the present invention, the acrylic ester compound represented by the following Formula 4 and/or the acrylic anhydride compound represented by the following Formula 5 is used as the acrylic compound: 
In Formulas 4 and 5, R2 is a hydrogen atom or an alkyl group. The alkyl group is preferably a C1-C4 alkyl group such as methyl group and ethyl group. Preferred R2 is a hydrogen atom or methyl group. R3 is an alkyl group, preferably a C1-C6 alkyl group such as methyl group and ethyl group. The specific acrylic compound of Formula 4 is methyl ester, ethyl ester or isopropyl ester of acrylic acid or methacrylic acid; and the specific acrylic anhydride compound of Formula 5 is acrylic anhydride or methacrylic anhydride.
The addition amount of the acrylic compound is 1 to 100 equivalents, preferably 1 to 20 equivalents, more preferably 1 to 5 equivalents based on the starting 2-adamantanone compound. If less than one equivalent, the yield of the 2-hydrocarbyl-2-adamantyl acrylate compound is reduced. If more than 100 equivalents, the batch efficiency is lowered and the purification of the product becomes difficult.
The acrylic compound is added to the reaction system in any manner and in any addition speed. For example, the acrylic compound may be added to the reaction system prior to the addition of the Grignard reagent and/or the organolithium compound. Alternatively, the acrylic compound may be added simultaneously with the Grignard reagent and/or the organolithium compound. Preferably, the acrylic compound is added after the addition of the Grignard reagent and/or the organolithium compound.
The reaction temperature is xe2x88x9270 to 200xc2x0 C., preferably xe2x88x9250 to 100xc2x0 C. If the reaction temperature is lower than xe2x88x9270xc2x0 C., the reaction rate is low. If higher than 200xc2x0 C., the control of the reaction becomes difficult or the side reaction occurs to reduce the yield. The reaction temperature at the addition of the Grignard reagent and/or the organolithium compound and thereafter, and the reaction temperature at the addition of the acrylic ester compound and/or the acrylic anhydride compound and thereafter may be the same or different, and each reaction temperature may be varied by heating and cooling within the range of xe2x88x9270 to 200xc2x0 C.
The reaction time for esterification is 0.5 to 1000 h, preferably 1 to 100 h, although not limited thereto because the reaction time depends on the reaction temperature and is determined according to the desired yield and another process factor.
R1 of Formula 6 representing the 2-hydrocarbyl-2-adamantyl acrylate corresponds to R1 of the Grignard reagent of Formula 2 and R1 of the organolithium compound of Formula 3, and R2 of Formula 6 corresponds to R2 of the acrylic ester compound of Formula 4 and R2 of the acrylic anhydride compound of Formula 5.
Although the objective 2-hydrocarbyl-2-adamantyl acrylate compound is produced in sufficiently high yields under reaction conditions mentioned above, the yield can be further enhanced by carrying out the reaction in the presence of an amine compound when the acrylic anhydride compound is used as the acrylic compound. Examples of the amine compound include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, di-isopropylamine, tri-n-propylamine, n-butylamine, di-n-butylamine, di-isobutylamine, tri-n-butylamine, diphenylamine, 1,5-diazabicyclo[4.3.0]nonene-5, 1,5-diazabicyclo[5,4,0]undecene-5, and diazabicyclo[2.2.2]octane, with triethylamine being particularly preferred.
The reaction may be carried out, in addition to the amine compound, in the further presence of an aniline compound such as aniline, methylaniline, dimethylaniline, toluidine, anisidine, chloroaniline, bromoaniline, nitroaniline, and aminobenzoic acid; a nitrogen-containing heterocyclic compound such as a pyridine compound, a pyrrole compound, a quinoline compound, and a piperidine compound; a metal alkoxide such as sodium methoxide and lithium methoxide; a quaternary ammonium hydroxide such as tetramethylammonium hydroxide and trimethyl-n-propylammonium hydroxide; a sulfate, nitrate or hydrochloride of amine such as ethylammonium sulfate, trimethylammonium nitrate and anilinium chloride; or an inorganic base such as sodium hydrogencarbonate.
The addition amount of the amine compound is up to 100 equivalents excluding zero, preferably 0.000001 to 10 equivalents, more preferably 0.01 to 2 equivalents based on the starting 2-adamantanone compound. The use of the amine compound exceeding the above range creates no additional effect of enhancing the yield.
The manner for addition and the addition speed of the amine compound is not particularly limited. For example, the amine compound may be added to the reaction system prior to the addition of the organometallic compound (Grignard reagent and organolithium compound). Alternatively, the amine compound may be added to the reaction system after the addition of the organometallic compound, and before, simultaneously with or after the addition of the acrylic anhydride compound.
After completing the reaction, the reaction liquid is washed with water to remove the magnesium salt or the lithium salt derived from the Grignard reagent or the organolithium compound. The washing water may contain an appropriate inorganic salt such as sodium chloride and sodium hydrogencarbonate. The remaining non-reacted acrylic anhydride compound is removed by alkali washing using, but not limited thereto, an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution or an ammonia water. The metal impurities in the reaction liquid may be removed by acid washing using an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid and phosphoric acid or an aqueous solution of an organic acid such as oxalic acid. Since the remaining hydrochloric acid, even in a trace amount, decomposes the target compound during the distillation operation, it is preferred to used the inorganic acid other than hydrochloric acid.
An organic solvent may be added to the reaction liquid prior to the washing, if desired, in view of the properties of the produced 2-hydrocarbyl-2-adamantyl acrylate compound. The solvent to be added is the same as or different from the solvent used in the reaction. Usually, a low polar solvent which is easily separable from water is preferably used. The 2-hydrocarbyl-2-adamantyl acrylate compound is separated from the organic layer by a known method such as distillation, concentration, filtration, crystallization, recrystallization and column chromatography.